Conceivable, yes. That seems to be where my mt bike cassettes wear out first. It's also smaller than the other rings so it gets more 'use' per cassette rotation.

It's POSSIBLE . . . probably if a person ran the bike on a trainer in the 11T all the time. But I doubt that's the problem.

I think it's more likely that the rear derailleur is out of adjustment. The derailleur stop is probably set too far toward the cassette. But I would start over -- set all three stops and the cable -- just to make sure.

Thanks. Just put it together that it might be the chain length ... I had swapped them out recently.

Appreciate the replies.

You wouldn’t happen to be using a Wipperman chain link? I’ve seen this happen with this quick link installed with the wrong side towards the rings/cogs.

I am indeed using a Wipperman. Lemmie look at the quick link.

While you're looking things over, look for a bent tooth. I've run into that problem in the past.

Couple debugging tips

Does it make a lot of noise at the other end of the cassette? If so have your hanger alignment checked. (This is my go to fix, most hangers are made out of super soft aluminum and go out of whack if you look at them wrong)

Put the bike in a stand and in the 11 tooth...spin the pedals...does one link jump? If so it might be a stiff link or the quick link mentioned earlier.

Last but not least....try switching the 11 tooth out....most can be swapped with any other 11 tooth. See if that fixes it.